Draws a grid on a particular face of a box in 3-space (for use with selected TDPACK routines).
Available in version 4.3.1 and later.
procedure tdgrid ( wks  : graphic, xbegin  : float, xstep  : float, nx  : integer, ybegin  : float, ystep  : float, ny  : integer, grid_flag  : integer )
xbegin and xstep are float scalars that define where ticks or grid lines are to be drawn along the X axis of the parallelogram. nx indicates how many ticks/lines to draw (xbegin, xbegin+xstep, xbegin+2*xstep, ... xbegin+(nx-1)*xstep).ybegin
ybegin and ystep are float scalars that define where ticks or grid lines are to be drawn along the Y axis of the parallelogram. ny indicates how many ticks/lines to draw (ybegin, ybegin+ystep, ybegin+2*ystep, ... ybegin+(ny-1)*ystep).grid_flag
Integer flag that defines what is to be drawn: 1 (draw just a perimeter), 2 (draw a perimeter with inward-pointing ticks), or 3 (draw a perimeter with a grid).
This routine is part of the low-level TDPACK package, which is a group of Fortran and C callable routines for projecting objects from a 3-dimensional coordinate system having U, V, and W axes to a 2-dimensional projection plane having X and Y axes and/or for drawing the projections of those objects. This can be referred to somewhat loosely as "drawing objects in three dimensions".
This procedure draws a perimeter, optionally with ticks or grid lines, around the edges of the reference parallelogram defined by the last call to tdpara. This routine is normally called indirectly (by virtue of a call to tdgrds), but there is no reason why it should not be called directly.
Please see the documentation on TDGRID for a full description of this procedure.
Grid drawing routines: tdgrds, tdgrid